Has anyone ever swapped a Piston into an RX-8?
#1
Registered
Thread Starter
Has anyone ever swapped a Piston into an RX-8?
Mod Edit: This was bumped from the grave...
I'm trying to see what kind of stuff people has to go through when RX-8 gets a different engine.
I can see fab on Engine mount, Exhaust down pipe and transmission mating. But I'm interested in ECU wiring to the car, like the tech meter and door sensors and remote door locks.
Thanks
And please don't flame for pulling out the RENESIS. It'll probably go into a Track Only car.
I'm trying to see what kind of stuff people has to go through when RX-8 gets a different engine.
I can see fab on Engine mount, Exhaust down pipe and transmission mating. But I'm interested in ECU wiring to the car, like the tech meter and door sensors and remote door locks.
Thanks
And please don't flame for pulling out the RENESIS. It'll probably go into a Track Only car.
Last edited by RIWWP; 09-04-2013 at 12:34 PM.
#2
Registered User
Join Date: May 2007
Location: Lowell, Mass
Posts: 414
Likes: 0
Received 0 Likes
on
0 Posts
yea there are a few rx7s out there with piston engines.. i believe the common swap is a LS1 might be wrong thou.. also i read on this forum the other day someone is in the process of swapping a 2jz in an RX8 which id love to see a video of that at a track.. so yes its not uncommon to read about rotaries gettin swapped out for piston engines..
#4
Registered
Thread Starter
I've seen them as well. But I'm concerned about the electronics inside the RX-8 working with the piston engine's ECU.
This is not going to be a race car but a daily driver with enough torque and gas mileage. (around 130-170 wheel torque @ 3,000-3,500 RPM and 22MPG city). The RENESIS gets 80 Torque at that RPM and 15MPG in city.
I'm considering a rebuilt Nissan KA24DE with small turbo at 5psi boost. The KA24DE is a very simple and cheap engine in both mechnical and eletrical parts.
This is not going to be a race car but a daily driver with enough torque and gas mileage. (around 130-170 wheel torque @ 3,000-3,500 RPM and 22MPG city). The RENESIS gets 80 Torque at that RPM and 15MPG in city.
I'm considering a rebuilt Nissan KA24DE with small turbo at 5psi boost. The KA24DE is a very simple and cheap engine in both mechnical and eletrical parts.
Last edited by Soravia; 12-31-2007 at 01:13 PM.
#5
Spin Triangles! Spin!
Join Date: Mar 2005
Location: Texas, US
Posts: 827
Likes: 0
Received 0 Likes
on
0 Posts
On kind of a side note...if you search the site there is someone who posted their v8 Rx-8. I beleive there were even pictures. But ti was a loooong time ago.
________
Fantasydoll cam
________
Fantasydoll cam
Last edited by dmorales; 09-09-2011 at 03:28 AM.
#6
Registered
Join Date: Jan 2006
Location: Orlando, FL
Posts: 172
Likes: 0
Received 0 Likes
on
0 Posts
I've encountered a 2nd gen RX-7 with a V8 at Roebling Road. Thought it was my friend in his regular RX-7 until we hit the straight away. It was crazy fast down the straight. I think the V8 would change the balance of the car though.
#7
Registered
Thread Starter
Not if it's a small V8.
This is not going to be V8, it's not about power. It's about Torque/Gas Milage.
I've read someone mention on the forum about having 2 ECU. I suppose I can have the KA24DE ECU running the engine and the RENESIS ECU reading out the engine speed and electrical sensors such as ABS, Door, oil pressure, TEMP, DSC, Headlight etc.
Is that possible? I think the Check Engine light will be on all the time. (I'll be disabling the ABS though. I hate that thing)
This is not going to be V8, it's not about power. It's about Torque/Gas Milage.
I've read someone mention on the forum about having 2 ECU. I suppose I can have the KA24DE ECU running the engine and the RENESIS ECU reading out the engine speed and electrical sensors such as ABS, Door, oil pressure, TEMP, DSC, Headlight etc.
Is that possible? I think the Check Engine light will be on all the time. (I'll be disabling the ABS though. I hate that thing)
Last edited by Soravia; 12-31-2007 at 01:50 PM.
#10
Registered
Thread Starter
I don't think it'll be too much to pop in a Nissan KA24DE engine. Junk yards sells them for $300. With tranny and ECU the whole deal it should be like $600.
Mounts and Exhaust will need to be fabbed. The KA24DE wiring is exretmely simple so that's no issue either. Time and place can be rented cheap too.
The real issue is to have the KA24DE engine working with the Sensor read outs in the RX-8 gauges and to have the KA24DE engine mate to the RX-8 Manual Transmission. EDIT : Steering rack will need to convert to hydrolyics too.
Estimated total cost of a fully rebuilt stock spec KA24DE (with higher compression and reprogrammed ECU) would set me no more than $1,500.
Correct me if I'm wrong, I believe that on identical cars with identical drivetrain engine with higher torque per liter of air (and by extension also gas) would make better mileage than engine with same liter of air but lower torque.
Here are the Dyno for both engines at the wheel. All Stock.
RENESIS
KA24DE
Mounts and Exhaust will need to be fabbed. The KA24DE wiring is exretmely simple so that's no issue either. Time and place can be rented cheap too.
The real issue is to have the KA24DE engine working with the Sensor read outs in the RX-8 gauges and to have the KA24DE engine mate to the RX-8 Manual Transmission. EDIT : Steering rack will need to convert to hydrolyics too.
Estimated total cost of a fully rebuilt stock spec KA24DE (with higher compression and reprogrammed ECU) would set me no more than $1,500.
Correct me if I'm wrong, I believe that on identical cars with identical drivetrain engine with higher torque per liter of air (and by extension also gas) would make better mileage than engine with same liter of air but lower torque.
Here are the Dyno for both engines at the wheel. All Stock.
RENESIS
KA24DE
Last edited by Soravia; 12-31-2007 at 06:10 PM.
#12
DGAF
iTrader: (1)
Join Date: Jan 2006
Location: Austin, TX
Posts: 1,953
Likes: 0
Received 0 Likes
on
0 Posts
So you're going to spend thousands and work your *** off for slightly better gas mileage and a modest torque increase? You'd achieve your goals much more easily just putting a turbo on the renesis.
#14
Registered
Thread Starter
How would a Turbo RENESIS make better mileage than a NA RENESIS?
Please explain. I already know that the cost of a Turbo RENESIS is RX-8 Cost + $5,000 range.
As I mentioned before, the cost will be covered by selling the RENESIS.
The mileage cost between the RENESIS and KA24DE is $100 a month (30 miles a day) and $1,200 a year. $1,200 a year is the cost of one year insurance for RX-8 (varies by driver). That is IF the gas prices stay at $3.0 per gallon.
(I'm also planning out an E85 but they are hard to get in Florida)
Please explain. I already know that the cost of a Turbo RENESIS is RX-8 Cost + $5,000 range.
As I mentioned before, the cost will be covered by selling the RENESIS.
The mileage cost between the RENESIS and KA24DE is $100 a month (30 miles a day) and $1,200 a year. $1,200 a year is the cost of one year insurance for RX-8 (varies by driver). That is IF the gas prices stay at $3.0 per gallon.
(I'm also planning out an E85 but they are hard to get in Florida)
Last edited by Soravia; 12-31-2007 at 02:12 PM.
#16
DGAF
iTrader: (1)
Join Date: Jan 2006
Location: Austin, TX
Posts: 1,953
Likes: 0
Received 0 Likes
on
0 Posts
How would a Turbo RENESIS make better mileage than a NA RENESIS?
Please explain. I already know that the cost of a Turbo RENESIS is RX-8 Cost + $5,000 range.
As I mentioned before, the cost will be covered by selling the RENESIS.
The mileage cost between the RENESIS and KA24DE is $100 a month (30 miles a day) and $1,200 a year. $1,200 a year is the cost of one year insurance for RX-8 (varies by driver). That is IF the gas prices stay at $3.0 per gallon.
(I'm also planning out an E85 but they are hard to get in Florida)
Please explain. I already know that the cost of a Turbo RENESIS is RX-8 Cost + $5,000 range.
As I mentioned before, the cost will be covered by selling the RENESIS.
The mileage cost between the RENESIS and KA24DE is $100 a month (30 miles a day) and $1,200 a year. $1,200 a year is the cost of one year insurance for RX-8 (varies by driver). That is IF the gas prices stay at $3.0 per gallon.
(I'm also planning out an E85 but they are hard to get in Florida)
I think you're being inredibly optimistic about what this engine swap is going to cost. The turbo alone for that nissan engine is going to be more than $1200. When its all said and done you'll blow more money and have more headaches than you'll make back at the pump. If torque is your concern, turbo the renesis. If gas mileage is, drive conservatively. If its both, buy a different car and save yourself a lot of trouble.
#17
Registered
Thread Starter
My S-13 240SX with KA24DE makes 25-30MPG after removing emissions. (21-26MPG stock)
RX-8 I drove for a month made 15MPG on the same route to work and back.
The weight difference between Stock RX-8 and Stock S13 is exactly 300LB. Swapping the KA would make extra 70 or so on the weight but I'm expecting a reduction in weight by using lighter custom intake and exhaust manifold and moving the battery to keep near 50/50 weight.
The reason for the mod is not just the torque nor the milage. I just want the RX-8 chassis. Lighter than 350Z with same suspension setup, rear seats that I don't have to get out of driver seat to use, huge trunk space and great accident impact rating.
I'll be driving a Miata before I do the swap. Right now I'm driving a 240sx. Great handling car with torque for mileage, but poor interior and absolutely no insurance value.
Miata is just too small for accidents and I hate converts.
RX-8 I drove for a month made 15MPG on the same route to work and back.
The weight difference between Stock RX-8 and Stock S13 is exactly 300LB. Swapping the KA would make extra 70 or so on the weight but I'm expecting a reduction in weight by using lighter custom intake and exhaust manifold and moving the battery to keep near 50/50 weight.
The reason for the mod is not just the torque nor the milage. I just want the RX-8 chassis. Lighter than 350Z with same suspension setup, rear seats that I don't have to get out of driver seat to use, huge trunk space and great accident impact rating.
I'll be driving a Miata before I do the swap. Right now I'm driving a 240sx. Great handling car with torque for mileage, but poor interior and absolutely no insurance value.
Miata is just too small for accidents and I hate converts.
Last edited by Soravia; 12-31-2007 at 02:27 PM.
#19
Get a Corolla. Seriously. No one buys an RX-8 expecting good gas mileage. If someone did, that someone is a ******* idiot.
I get 11mpg mostly, and I still lulz at the gas prices. Gotta pay to play.
I get 11mpg mostly, and I still lulz at the gas prices. Gotta pay to play.
#20
Registered
Thread Starter
Any idea to make better mileage on the RENESIS? I think that part has laready been explored many times.
I don't think I can get any more info from the forum. I'll just go look on my own. At worst I'll endup with gauge pod infront of the OEM gauges.
I don't think I can get any more info from the forum. I'll just go look on my own. At worst I'll endup with gauge pod infront of the OEM gauges.
#21
Registered User
Join Date: Jul 2007
Location: new jersey U.S.A
Posts: 705
Likes: 0
Received 0 Likes
on
0 Posts
im going to tell u like this leave the 8 as a show car and get a project car
the 8 will never be a really fast car and for gas miles wait till spring and see what pops up
this is a drunk man telling you this muahahahahahaha
the 8 will never be a really fast car and for gas miles wait till spring and see what pops up
this is a drunk man telling you this muahahahahahaha
#22
DGAF
iTrader: (1)
Join Date: Jan 2006
Location: Austin, TX
Posts: 1,953
Likes: 0
Received 0 Likes
on
0 Posts
Part of the great RX-8 chassis comes from the size and placement of the engine. Throw in something else, and you'll diminish that. No telling how much, but it won't be the same.
#23
Registered
Thread Starter
I'm also lookig forward to the new engine as well. If it runs great for Torque/Mileage, I might end up getting that X16 engine.
Which is why I'm getting a Miata for now and leaving the 240SX in the garage for track use.
I thought the second injectors starts at 4,750 rpm???? No?
I shift the RX-8 at 3,000-,3500 RPM. On the 240SX I shift 2,500-3,000 RPM.
Many people are either "Get a V8 or Get a Civic" I don't want a V8 and I don't like Civic (any FWD). I like the RX-8 Body and I want it for that. I don't care what engine is running inside. Just trying to keep the gas cost down as I will be driving it daily. I don't see a reason to keep a great car in the garage and drive a beat up car every day. (unless it costs $100K)
Which is why I'm getting a Miata for now and leaving the 240SX in the garage for track use.
I thought the second injectors starts at 4,750 rpm???? No?
I shift the RX-8 at 3,000-,3500 RPM. On the 240SX I shift 2,500-3,000 RPM.
Many people are either "Get a V8 or Get a Civic" I don't want a V8 and I don't like Civic (any FWD). I like the RX-8 Body and I want it for that. I don't care what engine is running inside. Just trying to keep the gas cost down as I will be driving it daily. I don't see a reason to keep a great car in the garage and drive a beat up car every day. (unless it costs $100K)
Last edited by Soravia; 12-31-2007 at 02:46 PM.
#24
DGAF
iTrader: (1)
Join Date: Jan 2006
Location: Austin, TX
Posts: 1,953
Likes: 0
Received 0 Likes
on
0 Posts
I'm also lookig forward to the new engine as well. If it runs great for Torque/Mileage, I might end up getting that X16 engine.
Which is why I'm getting a Miata for now and leaving the 240SX in the garage for track use.
I thought the second injectors starts at 4,750 rpm???? No?
Which is why I'm getting a Miata for now and leaving the 240SX in the garage for track use.
I thought the second injectors starts at 4,750 rpm???? No?
And you may be right about 4,750 rpm, I wasn't sure. 3000 is where I shift when I want mileage.